China 
Africa 
Explore chapters and articles related to this topic
Diffusion Bonding
Published in Yoseph Bar-Cohen, Advances in Manufacturing and Processing of Materials and Structures, 2018
Zirconium-diboride-based composites such as ZrB2-SiC are widely accepted as promising ultra-high-temperature ceramics due to their excellent oxidation resistance as well as high-temperature properties (Yang et al., 2013b). Up to now, very few studies have been reported on the diffusion bonding of ZrB2-SiC, especially those aimed at high-temperature applications. Diffusion bonding of ZrB2-SiC to Nb was investigated using Ti foil (He et al., 2012) and Ni foam (Yang et al., 2013a) as interlayers, respectively, by Yang et al. In the case of Ti interlayer, in situ synthesized TiB whiskers array appeared in the reaction layer and served as a buffer layer for stress relief. When Ni foam was adopted, extensive ligaments merging and discontinuous interfacial bonding were found to be beneficial for joint stiffness improvement and stress release.
Epitaxial Growth of III-Nitrides on Si Substrates for Highly-Efficient LED Application
Published in Kuan Yew Cheong, Two-Dimensional Nanostructures for Energy-Related Applications, 2017
Guoqiang Li, Wenliang Wang, Yunhao Lin
Zirconium diboride (ZrB2) (Blake et al. 2012, Fleurence et al. 2013, Roucka et al. 2008), Scandium Nitride (ScN) (Moram et al. 2006, Norenberg et al. 2006), Al2O3 (Fenwick et al. 2009a, b), SiC (Abe et al. 2012, Fang et al. 2014, Komiyama et al. 2009) and SiN (Huang et al. 2002) are also applied as buffer layers. Nevertheless, all of these materials cannot be grown by in situ process, which adds the additional deposition process and increases the cost of GaN-based LEDs on Si substrates (Zhu et al. 2013). However AlN and step graded Al xGa1-xN buffer layer, etc. can be grown by in situ process and have been adopted in the epitaxial growth of GaN-based LED epitaxial materials on Si substrates (Chen et al. 2001, Feng et al. 2014, Kim et al. 2001, Cheng et al. 2006, Lahreche et al. 2000, Lu et al. 2004, Marchand et al. 2001, Ng et al. 2015, Pan et al. 2011, Xiang et al. 2011, Zhu et al. 2010) and significant progress has been achieved.
Characterization of the Transient Contact Heat Transfer between C276 Superalloy and 5CrMnMo
Published in Heat Transfer Engineering, 2023
Chi Zhang, Linlei Guo, Liwen Zhang, Renchao Chen, Kangjie Song
The TCC plays an important role in nuclear reactors, internal combustion engines, heat exchangers, electronic packaging, solidification forging, quenching etc. [3–6]. It received a lot of attentions in recent decades. Two kinds of contact heat transfer mainly occur between bodies. One is steady-state heat transfer in which the two bodies are contacted throughout the process and a relative stable heat flux flows from hot body to cold body. The other one is transient heat transfer in which one object contact counterpart progressively and a varying heat flux exist between two bodies. The TCC is recommended to be sensitive to the detective conditions. Tang et al. [7] measured the steady-state TCC of TC4/30CrMnSi pair in the temperature range of 200 °C − 350 °C and load range of 0 MPa − 150 MPa. Xing et al. [8] studied the steady-state TCC of 5CrMnMo/GH4169 and 5CrMnMo/TC11 in the interface temperature range of 320 °C − 550 °C and contact pressure range of 2.96 MPa − 15.68 MPa. Sponagle and Groulx [9] measured the TCC between aluminum with different thermal interface materials. These studies indicate the effect of pressure on TCC is significant while the effect of temperature is limited. Chen et al. [10] studied the steady-state TCC of HTA–C/ZrB2–SiC (high temperature inconel 718 alloy–carbon fiber reinforced zirconium diboride and silicon carbide-based composite) numerically and experimentally. They found the TCC decreases with the temperature increases from 630 K to 1100 K because of the radiative heat transfer at high temperatures.
Microstructure of ZrB2–ZrN directionally solidified eutectic composite by arc-melting
Published in Journal of Asian Ceramic Societies, 2018
Eric Jianfeng Cheng, Hirokazu Katsui, Takashi Goto
Zirconium diboride (ZrB2) and zirconium nitride (ZrN) are promising ultra-high-temperature ceramic materials owing to their high mechanical strength, electrical conductivity, and chemical stability [1,2]. Sintering of ZrB2 and ZrN is difficult because of their covalent nature and high melting points, 3310 and 3500 K, respectively. Therefore, they have been consolidated via pressure-assisted sintering techniques with sintering additives, such as Ni, Fe, and Cu [3–6]. Using such additives, however, significantly degrades the mechanical and chemical properties, particularly at high temperatures. It is known that ZrB2–ZrN produces a eutectic system under a nitrogen pressure of 1 MPa and a eutectic temperature of 3050 K. With more than 5 mass% of ZrB2, a two-phase composite was identified; the eutectic composition was determined at 44 mol% of ZrB2 [7]. Still, there are few studies on the formation of eutectic microstructures of the ZrB2–ZrN system in the literature.
Boride-nitride hardening of metal deposited by high-chromium flux-cored wire
Published in Welding International, 2020
E. N. Eremin, A. S. Losev, S. A. Borodikhin
Moreover, another effective method for hardening metal is alloying it with boron [5–7]. Boron compounds such as ferroboron, boron carbide, chromium diboride, and titanium diboride are used for surfacing [8–10]. In earlier research, the authors found a positive influence of titanium diboride and zirconium diboride on the wear resistance of chromium-nickel maraging steels deposited with flux-cored wires [11,12]. The use of boron nitride, which is, owing to the similarity of a number of properties, an electronic analogue of carbon, is of particular interest for these purposes [13]. However, a combination of boron and nitrogen compounds is not used in chromium flux-cored wires, which produce a wear-resistant deposited metal.